Why can't I send my Litecoin out?

If you're getting a red box around your Litecoin TO address, and the SEND button won't light up, like this:

...you'll need to convert the Litecoin Address that begins with " 3" to an address that begins with "M." Please browse to this link in order to convert your 3-format address into an M-format Litecoin address.

If you send Litecoin to the new M-format address, it will go to the original 3-format Litecoin address.

Explanation

“Normal” BTC addresses start with a "1". "Script" BTC addresses like multi-sig and SegWit start with a "3".

LTC changed the "1" to an "L" so all “normal” Litecoin addresses start with an "L". The script addresses weren't changed from "3" so both Litecoin and Bitcoin shared the "3" for a while and addresses would work on both. Basically, there was no way to know if the "3" address is an LTC address or a BTC address. To fix this, LTC changed their address prefix to "M". This doesn’t break anything, it just makes it so visually the address should change and display starting with an "M".

Exodus used to allow both types for LTC, but when SegWit activated, people started using "3" addresses more often. That created a problem because people starting sending LTC to BTC addresses by mistake, and vice versa. To prevent that, we stopped accepting the old outdated "3" addresses for LTC. It is in the changelogs:

Some services haven't switched to using the new prefix so they still display LTC addresses with a "3". Those services need to update their code, but that isn't practical for users. A “manual fix” is you can convert the "3" address to an "M" address using this tool:
https://litecoin-project.github.io/p2sh-convert/

As always trying first with a small amount is a good idea. Make sure that the conversion link site is authentic before using!